The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.
Medical personnel generally use a wooden spatula in one hand to depress the tongue of a subject when examining the oral cavity. To provide adequate illumination for the examination, the medical personnel must also direct light into the oral cavity, which generally involves the use of the other hand. The use of both hands can present difficulties for medical personnel as it may be advantageous to have a free hand for holding the subject's head in place when performing the examination, especially when the subject is a child.
U.S. Pat. No. 4,643,172 describes a luminescent tongue depressor having a luminiferous depressor element connected to a handle. An illuminating means, in the form of a monatomic gas contained within a vacuum tube, is positioned within the handle to illuminate the depressor element. Light dispersing grooves in the depressor element act to disperse the light transmitted from the illuminating means through the depressor element in the mouth. In use, a removable sheath may be used to protect the depressor element.
U.S. Pat. No. 5,656,014 describes an illuminated tongue depressor having an elongated unitary body with a depressor blade at one end and a battery at the other. The depressor blade is longitudinally curved, and has a lamp positioned on the blade so that in use the physician's hand is lowered relative to a patient's mouth. A sanitary sheath may be pulled over the depressor blade in use.
The use of a sheath in both U.S. Pat. Nos. 4,643,172 and 5,656,014 may be disadvantageous. For example, to remove the sheath from the depressor element or blade, an operator may need to handle a portion of the sheath which has been in contact with a patient's mouth. Furthermore, while the sheath may be sterile the depressor blade may require cleaning. This may make these tongue depressors less hygienic and more difficult to use.
To assist in examining a patient it may be advantageous to also generate light contrast within the oral cavity, which would make it easier for an operator to identify certain features within the oral cavity, such as swelling. It may be difficult to provide sufficient light contrast when using a wooden spatula and a torch, or with a lamp positioned towards the end of the depressor blade as in U.S. Pat. No. 5,656,014. Furthermore, the tongue depressor described in U.S. Pat. No. 4,643,172 is designed to be substantially omniluminescent and use of an omniluminescent depressor would provide even light within the oral cavity, generating minimal light contrast.
U.S. Pat. No. 4,807,599 discloses an illuminating tongue depressor which includes a handle and a depressor blade which may be decoupled from the handle. The blade is constructed of a light-conducting synthetic resin material of relatively thin cross-section. A light source is provided at the proximal end of the blade, and light is directed along the blade to the distal end. A relatively complex blade decoupling mechanism is provided in this tongue depressor, complicating manufacturing. Furthermore, the handle includes a large number of components which may also complicate manufacturing.
Accordingly, there is a need to provide a tongue depressor that is easy to use, relatively simple to manufacture and/or which in use provides a contrast in light within the oral cavity.